Capture vs Castor: two self-serve platforms, tested side by side
Castor and Capture both serve biotechs and academic teams that want to run studies themselves. The differences show up when you build a real protocol: how the draft gets made, what sits in the same study, and how you get to live.
- Free sandbox, no sales call
- EDC, ePRO, eConsent, randomization
- Part 11-aligned controls
Free sandbox · No credit card · 21 CFR Part 11 aligned
Tests
5
Hands-on
4
To confirm
1
- Rebuild one of your real formsSame test, both systems
- Break an edit check and follow the querySame test, both systems
- Complete a questionnaire on a phoneSame test, both systems
- Sign a test eConsentSame test, both systems
- Compare total cost for your studyAsk both vendors
Capture vs Castor: the short version
- Castor, founded in the Netherlands, offers EDC, eCOA and eConsent and is widely used by academic groups and biotechs.
- Both platforms let study teams build studies themselves rather than relying on a vendor build team.
- Capture's AI Study Generator drafts visits, windows and forms from the protocol, so the first testable draft arrives quickly.
- Randomization with stratification, blinded roles and kit dispensing are built into Capture, in the same study as EDC, ePRO and eConsent.
- The fairest comparison is hands-on: build the same visit in both systems and compare the effort and result.
0
sales calls needed to start building
1
audit trail across EDC, ePRO, eConsent and randomization
Free
sandbox with every feature, no time limit
EU + US
hosting in Frankfurt or N. Virginia
The comparison
Similar audiences, different build experiences
Castor and Capture often end up on the same shortlist because they target similar teams: small sponsors, academic groups and CROs that want control of their build and a system that is approachable for sites. On paper, the feature lists overlap a great deal. That is exactly why a paper comparison rarely decides it.
What decides it is the experience of building and running your study. Upload your protocol to Capture and review the drafted schedule and forms; build the same visit in Castor; then enter data, trigger an edit check, consent a test participant and export. Time each step and note what you had to work around.
Hosting
Capture hosts studies in the EU (Frankfurt) or the US (N. Virginia), chosen at setup, with AES-256 encryption at rest and TLS in transit. Ask each vendor where your specific study data will live.
What to compare
What to test when comparing Capture and Castor
| Criterion | Why it matters | Capture |
|---|---|---|
| Study build | Time from protocol to testable study | AI drafts visits and forms from the protocol; your team reviews and approves |
| Modules in one study | Reconciliation and vendor count | EDC, ePRO, eConsent, randomization and kits with one audit trail |
| Randomization | Blinding and supply | Stratified block randomization, blinded roles and kit dispensing built in |
| Data cleaning | Clean data at entry | Range and custom-value edit checks raise auto-queries; one query list |
| Compliance controls | Part 11 and GCP expectations | Field-level audit trail, re-authenticated e-signatures, role-based access |
| Commercial model | Fit for your study size | Free sandbox; no setup fee; pay only when you go live |
This table shows Capture's answers only. Ask Castor for theirs, and confirm current capabilities and terms directly with them.
Self-serve build
Your team builds and amends, with AI doing the drafting
The AI form builder drafts questions or lab tables from a description or an uploaded file, and the AI Study Generator drafts the schedule from your protocol. Nothing is saved without human review. Forms move from draft to approved and are locked for live use, so amendments are deliberate and recorded.
- Ten question types plus repeating table sections.
- Calculated fields such as BMI, BSA, eGFR and QTc.
- Configuration export and import between studies.
Question form
CRF or ePRO
Lab table
Analytes, units, ranges
- Number
1. Systolic blood pressure
Required · Number · mmHg · 0 dp
- Number
2. Diastolic blood pressure
Required · Number · mmHg · 0 dp
- Number
3. Pulse rate
Required · Number · beats/min
- Number
4. Body temperature
Required · Number · °C · 1 dp
- Single choice
5. Position during measurement
Required · Sitting, Supine, Standing
- + 9 more questions
One platform
EDC, ePRO, eConsent and randomization in one study
Sites enter data on locked, approved forms with edit checks that raise queries at entry. Participants complete questionnaires on their own phones and sign eConsent with verified signatures. Randomization and kit management run in the same study, and everything shares one field-level audit trail.
- One participant record across every module.
- No integrations to build or reconcile.
- Phase 1 through Phase 3.
Build the same form in Capture
Free sandbox with every feature. No credit card.
Fit
When Castor fits, and when Capture does
Castor is often a good fit for teams already running studies on it, academic groups with institutional agreements in place, and studies that depend on workflows or integrations your team already knows well.
Capture fits teams that want an AI-drafted first build from the protocol, randomization and kit management in the same study, and a free sandbox to test everything before paying.
Compliance controls
The controls inspectors look for, built in
Every change is written to an append-only, hash-chained audit trail with user, time, old and new value and reason. Electronic signatures require password re-authentication and carry a meaning statement. Roles separate sites, and identifying data is segregated from study data at the database layer.
- Field-level audit trail, never hard deleted.
- Re-authenticated e-signatures.
- Role-based access with site separation.
Weight changed 68.0 to 68.5 kg
Site coordinator · Reason: Transcription error
Query Q-0014 answered on Weight
Site coordinator · Reason: Source checked
Vital signs form locked
Data manager · Reason: Visit cleaned
Switching
Moving from Castor to Capture
Start your next study in Capture rather than moving a running one. Export your form definitions or a data dictionary and upload it; Capture's AI drafts the forms for review, and standard forms come from the template library.
Historical data stays in its original export and is combined at analysis if needed. See how to switch EDC vendors mid-study for when a mid-study move makes sense.
Evaluation
How to compare EDC vendors side by side
Same form in both systems
Build one real form with edit checks.
Site workflow
Enter data, raise and answer a query.
Participant workflow
Consent and a questionnaire on a phone.
Monitoring
Set SDV and review what a monitor sees.
Exports
Data dictionary, codes and labels.
Total cost
Setup, per-site and per-participant fees.
All comparisons
Compare Capture with other platforms
Every comparison uses the same approach: what to test, where each option fits, and Capture's own answers. See all of them on the comparisons hub at /compare.
Is Capture a Castor alternative?
Yes. Capture offers EDC, ePRO, eConsent and randomization in one self-serve study, with AI drafting from the protocol.
Can I move my Castor forms to Capture?
Export your form definitions or data dictionary and upload them; the AI drafts the forms for your review.
Which is better for academic studies?
Both are used in academic research. Test your own protocol in each; Capture's sandbox is free with no time limit.
Can I test Capture before deciding against Castor?
Yes. The free sandbox includes every feature with sample data, no credit card and no time limit. You pay only when you go live.
How did you build this comparison?
From public positioning and the criteria teams tell us matter. We state only Capture's own capabilities as fact; confirm Castor's current offering with them.
Keep exploring
Related pages
Castor alternatives
A broader alternatives guide.
REDCap vs Castor
Another common comparison.
Capture vs Viedoc
EDC with patient modules, from Sweden.
Capture vs Medrio
EDC and eCOA for early-phase and mid-sized studies.
Capture vs OpenClinica
Cloud EDC with an open-source heritage.
Capture vs Clinion
eClinical platform including EDC.
Compare Capture against your shortlist
Free sandbox with every feature. No sales call.